Why jostled? I thought one of the bigger selling points of SSD is that they have no moving parts that can be damaged by abrupt movement?

Mechanical failure is very common on PCBs, especially ones with thousands of solder pads and aging solder joints.

I keep a plastic lap pad under my laptop when carrying it around horizontally. I see people just letting the whole torque of the laptop bend the motherboard and it hurts me. Those laptops will one day not POST because the CPU, RAM, or GPU will have a pad lifted off the PCB.

The Thinkpad T40 series was notorious for this, the chassis is relatively flexible, so the GPU would eventually let go of the mainboard.